JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foofoo" class="bar">Hello</div>
<div class="bar">World</div>

JavaScript

(function () {

    var basic = function (selector) {
        this.elements = document.querySelectorAll(selector);
        return this;
    }

    basic.prototype.print = function () {
        console.group("in print");
        console.log(this.elements[0].innerHTML);
        console.groupEnd("in print");
        return this;
    }

    basic.prototype.printAll = function () {
        console.group("in printAll");
        for (var i = 0; i < this.elements.length; i++) {
            console.log(this.elements[i].innerHTML);
        }
        console.groupEnd("in printAll");
        return this;
    }


    var foo = function (selector) {
        return new basic(selector);
    }

    window.foo = foo;

})();

console.group("id");
foo("#foofoo").print();
console.groupEnd("id");
console.group("class");
foo(".bar").printAll().print();
console.groupEnd("class");